Deciduous Shrubs Research Articles

Foraging preferences of the threatened coastal California Gnatcatcher ( Polioptila californica ) during the non-breeding season

We studied the foraging behavior of the federally threatened coastal California Gnatcatcher (<em>Polioptila californica</em>), an obligate insectivore, during the non-breeding season, a period of reduced survivorship for this non-migratory passerine due to seasonal aridity and the onset of cold winter storms. During the seasonal dry period in fall (October–November), California Gnatcatchers preferentially foraged in fall-blooming shrubs such as coyote brush (<em>Baccharis pilularis</em>), and California brickelbush (<em>Brickellia californica</em>). Upon the onset of the wet winter period (December–January), foraging California Gnatcatchers demonstrated a seasonal shift toward drought deciduous shrubs then leafing out, especially coastal sagebrush (<em>Artemisia californica</em>). Our findings suggest that California Gnatcatchers shift their foraging preferences seasonally to track available food resources. Additionally, our findings point to the value of floristic diversity within California Gnatcatcher habitat to provide year-round foraging opportunities for this obligate insectivore.

Larvicidal efficacy of Vangueria spinosa Roxb. (Rubiaceae) leaf extracts against filarial vector Culex quinquefasciatus

Culex quinquefasciatus is the transmitter of some dreadful vector-borne diseases. Such diseases can be controlled by managing the vector population. In this study, the mosquito larvicidal activity of the leaf extracts of a deciduous shrub Vangueria spinosa was evaluated for the first time. Larval mortalities were assessed using crude and different solvent extracts of young leaves of V. spinosa with different concentrations following standard methods. Thin-layer chromatography was done to characterize the major bioactive components liable for larval mortality. Cent percent mortality of the third instar larvae of Cx. quinquefasciatus was recorded at 2.5% concentration of crude extract within 48 hrs. Chloroform: Methanol extract was found to be the deadliest and 100% mortality of third instar larvae was reached in 48 hrs at 50 ppm concentration. The active ingredient which seems to be mainly responsible for larval mortality was steroidal in nature. LC50 of the fraction was calculated as 13.34 ppm for third instar larvae in 24 hrs. No significant effect of these extracts was noted on non-target organisms. So, the leaf of V. spinosa can be used as a potential source for the preparation of mosquito larvicide.

New record of anthracnose disease in leaves of &lt;em&gt;Plumeria pudica&lt;/em&gt; in Sri Lanka

Plumeria pudica L. is a deciduous ornamental shrub that belongs to the family Apocynaceae and is widely cultivated in Sri Lanka as a cosmopolitan ornamental plant. It has been reported that the anthracnose disease affects many tropical and subtropical fruits, vegetables, and foliage plants. Colletotrichum gloeosporioides or C. acutatum were reported as pathogens presently accepted as species complexes. In January 2021, a new fungal disease was observed on P. pudica, within the premises of the Eastern University, Sri Lanka, Vantharumoolai, Sri Lanka. Symptoms initiated as irregular necrotic spots that enlarged with pale brown borders. Later, the spots turned grayish-black, nearly rounded without lesions and haloes on the adaxial side of the matured leaves. Diseased leaf samples (10) were collected from three different trees inside the premises. Small pieces of infected leaves were used to isolate the pathogen on Potato dextrose Agar ( PDA) following the standard protocols. Forty colonies with similar morphology were obtained from diseased leaves. The colonies were white to gray and olivaceous in reverse after seven days of incubation under 27 °C. The morphological characters of fungal colonies, conidia, and appressoria were consistent with those of Colletotrichum sp., isolated from several other ornamental plants. Thus, based on these morphological characteristics, the pathogen was identified as Colletotrichum sp. Pathogenicity of the fungus was confirmed by performing Koch’s postulates using healthy detached leaves of P. pudica. This is the first report of Colletotrichum sp. causing anthracnose in P. pudica in Sri Lanka. This finding warrants the species-level identification of the pathogen using molecular data. The present work also lays the foundation for future studies on managing the disease in P. pudica under nursery or marketing conditions.

Peculiarity of currant and perpetual repair cell culture

Perpetual raspberry is a group of raspberry varieties distinguished by their ability to bear fruit on two-year and one-year stem shoots. Black currant (Ríbes nígrum) is a deciduous shrub, family Gooseberry (Grossulariaceae), related to currants (Ribes). The article presents methods of cell selection of perpetual raspberries and currants. Crop varieties resistant to extreme natural factors, obtaining high harvest, and two harvests per year were considered. The chemical composition of the used nutrient medium, the content of micro- and macroelements, and organic substances were taken into account. The qualitative composition of callus shoots extracted from plant cells was determined. A strong relationship between the frequency of callusogenesis in black currant and the balance of phytohormones in the nutrient medium has been shown. Progress in the field of gene and cell biotechnology is directly related to the development of the basics of the cultivation of plant cells and tissues under in vitro conditions. In addition, it is of particular interest to choose a suitable nutrient medium, to establish the mode of cultivation in order to determine the species and volume of explants, the totipotency of representatives of different taxonomic groups of plants. At present, this unique ability of somatic cells is found in various cultures, most of which are annual and practically vegetative propagating plants. These are vegetable crops and ornamental plants, the list of which grows annually. The scientific novelty of the work is the possibility of obtaining somatic hybrids and transgenic plants of repair raspberry and black currant using biotechnology methods. Therefore, the study of theoretical foundations and development of applied aspects of cells and tissues of perennial plants, in particular fruit and berry and agricultural crops, their accelerated reproduction, obtaining somatic hybrids and transgenic plants are considered relevant.

Leaf Traits and Resource Use Efficiencies of 19 Woody Plant Species in a Plantation in Fangshan, Beijing, China

Plantations are typically monocultures, which limits their sustainability. Therefore, understanding acclimatization strategies and resource use efficiencies in plant species and life forms aids the improvement of vegetation diversity and ecological functions. Here, 19 species from forest plantations in Fangshan, Beijing, China were studied. We determined their net photosynthetic (Pn), and transpiration rates (E), light response curve, stomatal conductance (gs), and leaf nitrogen (N) content. We analyzed the leaf N content (Nmass), specific leaf area (SLA), maximum net photosynthetic rate (Pnmax), water use (WUE), nitrogen use (NUE), and carbon use (CUE) efficiencies and connected them with both species and life forms. Pnmax, SLA, Nmass, WUE, NUE, and CUE significantly differed among species. Evergreen conifers had the lowest SLA and Nmass but the highest WUE and CUE. Evergreen coniferous trees had lower SLA, Nmass, Pnmax, and NUE but higher WUE than deciduous trees and shrubs. The SLA, Nmass, and Pnmax of nitrogen-fixing plants were the highest. A correlation analysis revealed that WUE was positively correlated with CUE and negatively correlated with NUE. Moreover, WUE was negatively correlated with Nmass and SLA. These insights into the adaptability differences of woody plant species and life forms provide a scientific basis for the selection of appropriate species for sustainable forest plantations.

Effects of warming and litter positions on litter decomposition in a boreal peatland

Litter decomposition is an important source of carbon accumulation in the permafrost peatlands. Climate warming has led to shrub expansions and accelerated litter mixing with soils and fluctuations in the water table. However, little is known about how changes in the position of the litter will affect litter decomposition under climate warming. To reveal the mechanisms of response of the location of litter in the soil and climate warming to litter decomposition in permafrost peatlands. Here, we selected the evergreen shrub,Chamaedaphne calyculata, and the deciduous shrub,Vaccinium uliginosum, from the permafrost peatlands of the Greater Hing’an Mountains, China. The leaf litter was placed on the soil surface (no-mixing) and mixed with the soil (soil-litter mixing), and then it was incubated for 124 days at 15°C (control) and 20°C (warming). Our results showed that warming significantly increased the CO2emission rates ofC. calyculataandV. uliginosumby 19.9 and 17.4%, respectively. When compared to no-mixing, the CO2emission rates were reduced (not significantly) by 1.5 (C. calyculata) and increased 13.6% (V. uliginosum) with soil-litter mixing. Interestingly, soil-litter mixing suppressed the positive effect of warming on the CO2emission rates relative to no-mixing, and the suppressing effects in theV. uliginosumsubplot were stronger than those in theC. calyculatasubplot. Specifically, warming significantly increased the CO2emissions ofC. calyculataby 27.4% under no-mixing but the increase decreased to 13.1% under soil-litter mixing. Similarly, warming induced significant increases in the CO2emissions ofV. uliginosum, with an increase of 38.8% under no-mixing but non-significant increases (1.9%) were observed under soil-litter mixing. The combination of the enzyme activities of β-1,4-glucosidase, β-1,4-xylosidase and β-D-1,4-cellobiosidase and laccase and phenolics explained more than 60.0% of the variability in the CO2emissions ofC. calyculataandV. uliginosum, respectively. Our study highlights the importance of litter positions in mediating the responses of litter decomposition to climate warming and shrub expansions in the northern peatlands.

Stoichiometry and stable isotopes of plants and their response to environmental factors in boreal peatland, Northeast China

The alterations of plant composition and diversity pose a threat to the stability of the carbon pool in boreal peatland under climate change. We collected the samples of three plant functional types (deciduous shrubs, evergreen shrubs, and sedge) in seven permafrost peatlands of the Great Hing’an Mountains, China, and measured the properties of total carbon (TC), nitrogen (TN), and phosphorus (TP), their stoichiometric ratios (C:N, C:P, and N:P), and the stable isotope values (δ13C and δ15N) of six tissues (ranging from leaves to roots). For TC, TN, and TP, the contents had an average of 470.69 ± 1.56, 8.03 ± 0.23, and 1.71 ± 0.61 mg·g−1, respectively. TC contents of sedge were lower than those of shrubs for the whole plant. The allocations of N and P to shrub leaves were higher than to stems and roots. There was a similar trend of TN and TP contents, and stoichiometric ratios from leaves to roots between deciduous shrubs and evergreen shrubs. Shrubs and sedge have similar C: N in leaves and fine roots, while leaves of sedge C:P and N:P ratios were higher than shrubs, mainly showed that sedge is N and P co-limitation and shrubs are N limitation. The values of δ13C and δ15N were significantly higher in leaves and roots of sedge than those of shrubs, which means shrubs have higher nutrient acquisition strategies. These results support the shrubs are expanding in the boreal peatland under climate warming through nutrient competition. TC contents of all deciduous shrubs and sedge tissues were positively linear correlated to MAT and the values of δ13C and δ15N in sedge had significant relationships with MAT and MAP. Our results imply warming can increase plant photosynthesis in boreal peatland, and sedge was more sensitive to climate change. These findings would be helpful to understanding the responses of different plant tissues to climate changes in permafrost peatland.

Protective Effects of Hippophae rhamnoides L. Phenylpropanoids on Doxorubicin-Induced Cardiotoxicity in Zebrafish.

Hippophae rhamnoides L. is a deciduous shrub that contains many unique bioactive substances. This sea buckthorn possesses anticancer, antioxidant, anti-inflammatory, and cardiovascular protective properties. Herein, the effects of phenylpropyl compounds extracted from H. rhamnoides L. on doxorubicin (Dox)-induced cardiotoxicity were evaluated in zebrafish. Cardiac injury in zebrafish was induced using 35 μM Dox for 96 h, and 30 μM phenylpropanoid compounds were used as the protective treatment. The cardioprotective effects and mechanisms of the four phenylpropanoids were investigated using microscopy, behavioral analysis, acridine orange staining, western blotting, flow cytometry, and real-time quantitative polymerase chain reaction. The extracted phenylpropanoids could significantly relieve Dox-induced cardiac injury in zebrafish and inhibit cardiomyocyte apoptosis. The mechanisms of action were mainly related to the stability of mitochondrial biogenesis and function maintained by phenylpropanoids in zebrafish. To our knowledge, this is the first report on the protective effect of sea buckthorn against myocardial injury in zebrafish. Our findings provide support for the further research and development of sea buckthorn and its components.

In vitro propagation results of Sorbus aria 'Gran Sasso'

Sorbuses are deciduous trees or shrubs belong to the family Rosaceae, mainly use them as ornamental or medicinal, fruit plant. In this work, in vitro sterile culture of Sorbus aria ‘Gran Sasso’ was established on half-strength Murashige and Skoog (MS, 1962) basal medium, and examined its shoot and root productions. The ideal cytokinin concentration and type for in vitro shoot development (with more than five shoot per plant specimen) were 0.4 and 0.8 mg/l BA or BAR, lower dosages or other cytokinins (especially KIN) was not effective, however, KIN resulted the longest and widest leaves. After a short (48-hour) period of root stimulation on an induction medium containing 15 mg/l IBA auxin, the hormone-free medium containing 0.75 g/l activated charcoal proved to be the best, but even in this case, it was not possible to achieve a rooting rate better than 36.7%. Silver nitrate was not resulted rooting in every doses, although higher concentrations (2 and 5 mg/l) decreased average shoot number and effectively increased shoots’ length and leaf sizes.

Phytochemistry, health benefits, and food applications of sea buckthorn (Hippophae rhamnoides L.): A comprehensive review.

Sea buckthorn (Hippophae rhamnoides L.), an ancient miraculous plant, is of great interest because of its tenacity, richness in nutritional active substances, and biological activity. Sea buckthorn is a deciduous shrub or tree of the genus Hippophae in the family Elaeagnaceae. It is a pioneer tree species for soil improvement, wind and sand control, and soil and water conservation. Sea buckthorn contains many nutritional active components, such as vitamins, carotenoids, polyphenols, fatty acids, and phytosterols. Moreover, sea buckthorn has many health benefits, such as antioxidant, anticancer, anti-hyperlipidemic, anti-obesity, anti-inflammatory, antimicrobial, antiviral, dermatological, neuroprotective, and hepatoprotective activities. Sea buckthorn not only has great medicinal and therapeutic potential, but also is a promising economic plant. The potential of sea buckthorn in the human food industry has attracted the research interest of researchers and producers. The present review mainly summarizes the phytochemistry, nutrients, health benefits, and food applications of sea buckthorn. Overall, sea buckthorn is a dietary source of bioactive ingredients with the potential to be developed into functional foods or dietary supplements for the prevention and treatment of certain chronic diseases, which deserves further research.

Chromosomal-level genome and multi-omics dataset provides new insights into leaf pigmentation in Acer palmatum

Acer palmatum (A. palmatum), a deciduous shrub or small arbour which belongs to Acer of Aceraceae, is an excellent greening species as well as a beautiful ornamental plant. In this study, a high-quality chromosome-level reference genome for A. palmatum was constructed using Oxford Nanopore sequencing and Hi-C technology. The assembly genome was ∼745.78 Mb long with a contig N50 length of 3.20 Mb, and 95.30 % (710.71 Mb) of the assembly was anchored into 13 pseudochromosomes. A total of 28,559 protein-coding genes were obtained, ∼90.02 % (25,710) of which could be functionally annotated. The genomic evolutionary analysis revealed that A. palmatum is most closely related to A. yangbiense and A. truncatum, and underwent only an ancient gamma whole-genome duplication event. Despite lacking a recent independent WGD, 25,795 (90.32 %) genes of A. palmatum were duplicated, and the unique/expanded gene families were linked with genes involved in plant-pathogen interaction and several metabolic pathways, which might underpin adaptability. A combined genomic, transcriptomic, and metabolomic analysis related to the biosynthesis of anthocyanin in leaves during the different season were characterized. The results indicate that the dark-purple colouration of the leaves in spring was caused by a high amount of anthocyanins, especially delphinidin and its derivatives; and the red colouration of the leaves in autumn by a high amount of cyanidin 3-O-glucoside. In conclusion, these valuable multi-omic resources offer important foundations to explore the molecular regulation mechanism in leaf colouration and also provide a platform for the scientific and efficient utilization of A. palmatum.

Twenty-one year dynamics of vegetation from long-term plots in East European tundra

Twenty-one year dynamics of vegetation from long-term plots in East European tundra

Ethnopharmacology, Botanical Description and Phytochemistry of Premna barbata: An Unexplored Medicinal Plant Species from Lamiaceae Family

Objectives: Premna barbata Wall. ex Schauer; (Lamiaceae) is a deciduous shrub or tree known as Aganyo in folk language. The plant is widely used in treating various diseases traditionally, such as arthritic pain, dropsy, diarrhoea, fever, and herpes complex disease. However, comprehensive data on this medicinally important plant is not available in the literature. Therefore, this review aims to provide a detailed overview of the botanical description, ethnomedicinal use, phytochemistry, and pharmacological investigations of Premna barbata to provide a scientific consensus for future research investigations and to link its traditionally claimed use to scientifically proven results. Methods: Information regarding the plant was gathered from electronic databases such as Science Direct, PubMed, Web of Science, Wiley Online Library, ACS, Springer, SciFinder, Taylor and Francis, Google Scholar, Scopus and Journal websites. The scientific name of the plant was validated using The Plant List and The International Plant Names Index. Results: An exhaustive study of the accessible sources of Premna barbata confirmed its origin, distribution, and ethnomedicinal use. It has been used in the form of powders, juice, paste, and decoctions against various ailments. Phytochemical analysis revealed the presence of different phytoconstituents. Only antibacterial potential of the plant has been reported yet. Conclusion: By performing the literature search, Premna barbata showcased its importance in folkloric medicine as well as in ayurvedic medicine. Moreover, the collected information from various trustworthy sources shows that the plant holds many hidden potentials and can, therefore, be studied extensively for its quality control, pharmacognosy, phytochemistry and pharmacological activity. Furthermore, in-depth studies are required to discover key features which can help in future research work. An effort is required to investigate this plant species, which is found distributed in most unexplored regions as well as it needs to be preserved as it’s on the verge of extinction.

Beaver foraging patterns in a human-dominated landscape: Effects on woody vegetation and mammals

Beavers can change habitat composition by cutting down trees, digging, and damming activities, thereby affecting species richness and abundance. Although there is large body of literature regarding the effects of beaver activity on a wide range of taxonomic groups, relatively little is known about how space use by ungulates is affected by beavers in the human-dominated landscapes of Europe. Here, we present a case study from Denmark that investigated potential effects of beaver activity on mammals, with a special focus on roe deer and red deer. Beavers could either facilitate the presence of deer by providing food resources (increased abundance of deciduous trees and shrubs) or compete with them for resources. Using transect counts recording both cut and uncut stems of woody plants, we describe beaver browsing patterns, providing evidence that they either select for areas with higher woody vegetation richness and diversity, or alter woody plant species composition. We then assessed deer presence and relative abundance in relation to the distance from water and in areas with varying beaver activity. Our findings provide limited evidence for exploitative competition between beavers and roe and red deer, as roe and red deer avoided proximity to water in areas with high beaver activity, and deer numbers were higher in areas with low beaver activity. We speculate that the weak effect of beaver activity on deer (and/or vice versa) might be related to the large human impacts in the area, e.g., forest management, potentially superseding effects of interspecific competition. An improved understanding of the complex effects beavers can have on ungulates in human-dominated landscapes will be relevant for wildlife and forestry management, potentially being an important tool to reduce human-wildlife conflicts.

Physical and Mechanical Properties of Thermoplastic Composites Filled with Wood Flour of Underutilized Chaste Tree

The potential use of a lignocellulosic filler, Vitex agnus-castus plant (Chaste tree), which is a deciduous invasive shrub, in thermoplastic composites was investigated. The stems of chaste trees with a diameter of 5-10 cm from Mugla city, Western Turkey, were used for the study. The different amounts (0 to 50 wt%, by 10 % increments) of the wood flour passing through the screen openings of 0.237 mm were added to the polypropylene matrix. Premixed raw materials were put into the volumetric feeder of the twin-screw extruder. The extruder barrel temperature was gradually increased from 170 °C (feeding zone) to the die zone (190 °C) at a constant screw speed (40 rpm). Then, the dried granules were hot-pressed into the 4 mm thick WPC panels at 2 MPa and 190 °C for 5 min. 3 wt% of maleic anhydride grafted polypropylene (MAPP) was added as compatibilizer into the formulation. The WPCs showed an increase in the thickness swelling (0.58 to 5.68 %) as the amount of the filler increased from 10 to 50 wt% in the polypropylene. The bending strength of the polypropylene composites increased from 33.9 to 44.8 MPa as the amount of the chaste wood flour was increased to 30 wt%, but further increase caused the decrease in the tensile strength (25.7 MPa). As for the bending modulus, it increased from 815 to 3250 MPa when the wood content reached 50 wt%. The tensile modulus increased from 1690 to 2253 MPa when the wood content arised from 10 to 50 wt%. The tensile strength, tensile modulus, flexural strength and flexural modulus of the unfilled polypropylene were found to be 19.6 MPa, 1505 MPa, 30.2 MPa and 664 MPa, respectively. According to the test results, it was concluded that the 30-40 wt% of Vitex agnus-castus wood could be efficiently used in the polypropylene composites for the semi-building applications such as decking or siding. The evaluation of underused invasive chaste wood in the production of tWPC production may result in an effective way to utilize this resource.

Lessons from a tropical deciduous shrub species: leaf fall can play a more important role than rain in leaf budding

In the Cerrado, the sequential chaining of phenological events during the dry season is a pattern observed in many plant species. In this season, many plants completely lose their leaves, and soon after deciduous, there is an expressive production of leaf buds. In this study, we investigated the effect of irrigation and early defoliation on the triggering of leaf budding of the deciduous species Peixotoa tomentosa A.Juss. in the dry season of a seasonal environment with water restrictions. Therefore, we set up an experiment with three groups of plants: control (n = 15), irrigation treatment (n = 15), and removal treatment (n = 15), and after the complete deciduousness of the plants, we carried out phenological monitoring of the development of leaf buds in these plants. From July to August 2022, the leaf budding phenology of the 45 individuals was evaluated twice a week. To test whether there is a difference in the number of leaf buds between treatments, we built generalized linear mixed models (GLMMs). Plants in the removal treatment had a statistically higher number of leaf buds produced than the plants in the irrigation and control groups (P &amp;lt; 0.05). However, the control group and the irrigation treatment did not differ from each other (P &amp;gt; 0.05). We showed that early defoliation influenced the triggering of leaf buds in P. tomentosa, increasing the production of young leaves in their individuals in a seasonal environment with water restrictions. Irrigation was not able to break the dormancy of leaf buds. Our findings contribute to a better understanding of the triggering of vegetative phenophases in deciduous Cerrado plants, showing that leaf fall may play a more important role than rain in the production of leaf buds in the dry season.

Morphology and Phylogeny of Pestalotiopsis (Sporocadaceae, Amphisphaeriales) from Fagaceae Leaves in China.

Fagaceae is a family of flowering plants widely distributed in the Northern Hemisphere, including deciduous and evergreen trees and shrubs. Species of Pestalotiopsis are well-known agents of leaf spot diseases, but targeted sampling on Fagaceae is still missing. To determine the diversity of Pestalotiopsis species associated with Fagaceae leaf spot in China, investigations were conducted in the main areas of Fagaceae distribution from 2016 to 2021. Diseased leaf tissues were collected, and fungal isolates were obtained from leaf spots. In the present study, 43 isolates of Pestalotiopsis were studied based on combined morphology and phylogeny. As a result, 10 new species were identified, viz., Pestalotiopsis anhuiensis, P. castanopsidis, P. changjiangensis, P. cyclobalanopsidis, P. foliicola, P. guangxiensis, P. guizhouensis, P. lithocarpi, P. shaanxiensis, and P. silvicola, and six new host records were recognized. IMPORTANCE Pestalotiopsis is a common fungal genus inhabiting plant tissues as endophytes, pathogens, and saprophytes. Fagaceae is a plant family including many important tree species, such as Castanea mollissima and Quercus spp. In this study, diseased leaves of Fagaceae in China were investigated, and 16 Pestalotiopsis species were identified based on morphology and phylogeny of combined loci of internal transcribed spacers (ITS), the translation elongation factor 1-α (tef1), and the beta-tubulin (tub2) genes. Among these, 10 new species were found, and six new host records were revealed. Our study significantly updates the taxonomy of Pestalotiopsis and enhances our understanding of leaf diseases of Fagaceae hosts.

Plant functional type aboveground biomass change within Alaska and northwest Canada mapped using a 35-year satellite time series from 1985 to 2020

Changes in vegetation distribution are underway in Arctic and boreal regions due to climate warming and associated fire disturbance. These changes have wide ranging downstream impacts—affecting wildlife habitat, nutrient cycling, climate feedbacks and fire regimes. It is thus critical to understand where these changes are occurring and what types of vegetation are affected, and to quantify the magnitude of the changes. In this study, we mapped live aboveground biomass for five common plant functional types (PFTs; deciduous shrubs, evergreen shrubs, forbs, graminoids and lichens) within Alaska and northwest Canada, every five years from 1985 to 2020. We employed a multi-scale approach, scaling from field harvest data and unmanned aerial vehicle-based biomass predictions to produce wall-to-wall maps based on climatological, topographic, phenological and Landsat spectral predictors. We found deciduous shrub and graminoid biomass were predicted best among PFTs. Our time-series analyses show increases in deciduous (37%) and evergreen shrub (7%) biomass, and decreases in graminoid (14%) and lichen (13%) biomass over a study area of approximately 500 000 km2. Fire was an important driver of recent changes in the study area, with the largest changes in biomass associated with historic fire perimeters. Decreases in lichen and graminoid biomass often corresponded with increasing shrub biomass. These findings illustrate the driving trends in vegetation change within the Arctic/boreal region. Understanding these changes and the impacts they in turn will have on Arctic and boreal ecosystems will be critical to understanding the trajectory of climate change in the region.

Chemotaxonomic Markers for the Leaf Buds of Common Finnish Trees and Shrubs: A Rapid UHPLC MS Fingerprinting Tool for Species Identification.

In this study, a chemotaxonomic tool was created on the basis of ultra-high-performance liquid chromatography–mass spectrometry (UHPLC–MS) for the identification of 13 common Finnish deciduous trees and shrubs from their leaf bud metabolites. The bud extracts were screened with UHPLC–ESI–QqQ–MS and UHPLC–ESI–Q–Orbitrap–MS to discover suitable markers for each species. Two approaches were tested in the marker selection: (1) unique species-specific markers to obtain selective fingerprints per species and (2) major markers to maximise the sensitivity of the fingerprints. The markers were used to create two selected ion-recording-based fingerprinting tools with UHPLC–ESI–QqQ–MS. The methods were evaluated for their selectivity, repeatability, and robustness in plant species identification by analysing leaf buds from several replicates of each species. The created chemotaxonomic tools were shown to provide unique chromatographic profiles for the studied species in less than 6 min. A variety of plant metabolites, such as flavonoids, triterpenoids, and hydroxycinnamic acid derivatives, were found to serve as good chemotaxonomic markers for the studied species. In 10 out of 13 cases, species-specific markers were superior in creating selective and repeatable fingerprints.

Links between individual performance, trace elements and stable isotopes in an endangered caribou population

Foraging is a key behaviour, and several aspects of foraging remain to be investigated in many wild species. Low energy gain or reduced protein, nutrient, and mineral intake may explain poor individual condition, low reproductive output, high mortality, and, in extreme cases, population declines. Our study explores how foraging ecology, diet composition, and nutritional status could influence individual performance in an endangered population of caribou (Rangifer tarandus caribou). We measured stable isotope ratios of carbon (δ13C) and nitrogen (δ15N) as well as the concentration of 21 trace elements in hairs of 44 caribou (~ 50% of the population). Our results showed that the Atlantic-Gaspésie caribou population consumed mainly lichens, horsetails, deciduous shrubs, and deciduous trees. We found a correlation between diet (described using stable isotope ratios) and accumulation of trace elements in hair using a redundancy analysis, and we detected relationships between diet, trace elements and vital rates using logistic and Cox models. Pregnancy and calf survival probabilities were higher when the δ13C signature of female caribou was higher, and the adult survival probability was higher in caribou that had higher concentrations of zinc and sodium, and lower concentrations of cesium and manganese in their hair. Based on the correlation we found between nutrition and individual performance, our study suggests that nutrition may be an important factor to consider in the recovery of this endangered caribou population.